Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / clr / src / BCL / System / Security / Cryptography / SymmetricAlgorithm.cs / 1305376 / SymmetricAlgorithm.cs
using System.Diagnostics.Contracts; // ==++== // // Copyright (c) Microsoft Corporation. All rights reserved. // // ==--== //[....] // // // SymmetricAlgorithm.cs // namespace System.Security.Cryptography { [System.Runtime.InteropServices.ComVisible(true)] public abstract class SymmetricAlgorithm : IDisposable { protected int BlockSizeValue; protected int FeedbackSizeValue; protected byte[] IVValue; protected byte[] KeyValue; protected KeySizes[] LegalBlockSizesValue; protected KeySizes[] LegalKeySizesValue; protected int KeySizeValue; protected CipherMode ModeValue; protected PaddingMode PaddingValue; // // protected constructors // protected SymmetricAlgorithm() { // Default to cipher block chaining (CipherMode.CBC) and // PKCS-style padding (pad n bytes with value n) ModeValue = CipherMode.CBC; PaddingValue = PaddingMode.PKCS7; } // SymmetricAlgorithm implements IDisposable // To keep mscorlib compatibility with Orcas, CoreCLR's SymmetricAlgorithm has an explicit IDisposable // implementation. Post-Orcas the desktop has an implicit IDispoable implementation. #if FEATURE_CORECLR void IDisposable.Dispose() #if false { } #endif // false #else [System.Security.SecuritySafeCritical] // auto-generated public void Dispose() #endif // FEATURE_CORECLR { Dispose(true); GC.SuppressFinalize(this); } public void Clear() { (this as IDisposable).Dispose(); } protected virtual void Dispose(bool disposing) { if (disposing) { // Note: we always want to zeroize the sensitive key material if (KeyValue != null) { Array.Clear(KeyValue, 0, KeyValue.Length); KeyValue = null; } if (IVValue != null) { Array.Clear(IVValue, 0, IVValue.Length); IVValue = null; } } } // // public properties // public virtual int BlockSize { get { return BlockSizeValue; } set { int i; int j; for (i=0; iBlockSizeValue || (value % 8) != 0) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidFeedbackSize")); FeedbackSizeValue = value; } } public virtual byte[] IV { get { if (IVValue == null) GenerateIV(); return (byte[]) IVValue.Clone(); } set { if (value == null) throw new ArgumentNullException("value"); Contract.EndContractBlock(); if (value.Length != BlockSizeValue / 8) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidIVSize")); IVValue = (byte[]) value.Clone(); } } public virtual byte[] Key { get { if (KeyValue == null) GenerateKey(); return (byte[]) KeyValue.Clone(); } set { if (value == null) throw new ArgumentNullException("value"); Contract.EndContractBlock(); if (!ValidKeySize(value.Length * 8)) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidKeySize")); // must convert bytes to bits KeyValue = (byte[]) value.Clone(); KeySizeValue = value.Length * 8; } } public virtual KeySizes[] LegalBlockSizes { get { return (KeySizes[]) LegalBlockSizesValue.Clone(); } } public virtual KeySizes[] LegalKeySizes { get { return (KeySizes[]) LegalKeySizesValue.Clone(); } } public virtual int KeySize { get { return KeySizeValue; } set { if (!ValidKeySize(value)) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidKeySize")); KeySizeValue = value; KeyValue = null; } } public virtual CipherMode Mode { get { return ModeValue; } set { if ((value < CipherMode.CBC) || (CipherMode.CFB < value)) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidCipherMode")); ModeValue = value; } } public virtual PaddingMode Padding { get { return PaddingValue; } set { if ((value < PaddingMode.None) || (PaddingMode.ISO10126 < value)) throw new CryptographicException(Environment.GetResourceString("Cryptography_InvalidPaddingMode")); PaddingValue = value; } } // // public methods // // The following method takes a bit length input and returns whether that length is a valid size // according to LegalKeySizes public bool ValidKeySize(int bitLength) { KeySizes[] validSizes = this.LegalKeySizes; int i,j; if (validSizes == null) return false; for (i=0; i< validSizes.Length; i++) { if (validSizes[i].SkipSize == 0) { if (validSizes[i].MinSize == bitLength) { // assume MinSize = MaxSize return true; } } else { for (j = validSizes[i].MinSize; j<= validSizes[i].MaxSize; j += validSizes[i].SkipSize) { if (j == bitLength) { return true; } } } } return false; } [System.Security.SecuritySafeCritical] // auto-generated static public SymmetricAlgorithm Create() { // use the crypto config system to return an instance of // the default SymmetricAlgorithm on this machine return Create("System.Security.Cryptography.SymmetricAlgorithm"); } [System.Security.SecuritySafeCritical] // auto-generated static public SymmetricAlgorithm Create(String algName) { return (SymmetricAlgorithm) CryptoConfig.CreateFromName(algName); } public virtual ICryptoTransform CreateEncryptor() { return CreateEncryptor(Key, IV); } public abstract ICryptoTransform CreateEncryptor(byte[] rgbKey, byte[] rgbIV); public virtual ICryptoTransform CreateDecryptor() { return CreateDecryptor(Key, IV); } public abstract ICryptoTransform CreateDecryptor(byte[] rgbKey, byte[] rgbIV); public abstract void GenerateKey(); public abstract void GenerateIV(); } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved.
Link Menu

This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- RootNamespaceAttribute.cs
- TypeInfo.cs
- DataGridViewCellLinkedList.cs
- EncoderParameter.cs
- ApplicationException.cs
- EncryptedReference.cs
- CompiledQuery.cs
- TdsValueSetter.cs
- SelectionPatternIdentifiers.cs
- StartUpEventArgs.cs
- TextSelectionHighlightLayer.cs
- CacheOutputQuery.cs
- SafeRightsManagementEnvironmentHandle.cs
- Automation.cs
- StorageFunctionMapping.cs
- TransmissionStrategy.cs
- ListenerElementsCollection.cs
- COM2PropertyDescriptor.cs
- FilterException.cs
- IODescriptionAttribute.cs
- BindableTemplateBuilder.cs
- CurrencyManager.cs
- Application.cs
- ResourceType.cs
- Icon.cs
- SiteMap.cs
- LiteralSubsegment.cs
- CopyOfAction.cs
- Suspend.cs
- While.cs
- SHA512Managed.cs
- ToolboxItemCollection.cs
- SplitContainer.cs
- ListViewSortEventArgs.cs
- LogicalChannel.cs
- SecurityUtils.cs
- ListBoxItem.cs
- MenuItem.cs
- MetafileHeader.cs
- EnumType.cs
- FixedSOMContainer.cs
- NavigationEventArgs.cs
- DataTableReader.cs
- Crc32.cs
- XmlSchemaSubstitutionGroup.cs
- DependencySource.cs
- SqlInternalConnectionSmi.cs
- XmlILAnnotation.cs
- MimeImporter.cs
- WebPartCollection.cs
- Point4DConverter.cs
- Repeater.cs
- FixedSOMSemanticBox.cs
- Package.cs
- DataColumnMapping.cs
- _SSPISessionCache.cs
- AuthenticationModuleElementCollection.cs
- WebRequestModuleElementCollection.cs
- ZoneLinkButton.cs
- QueryOperationResponseOfT.cs
- ForEachAction.cs
- XmlAttributeProperties.cs
- RectangleGeometry.cs
- ObjectStateEntryBaseUpdatableDataRecord.cs
- recordstatefactory.cs
- NumberFormatter.cs
- TextBlockAutomationPeer.cs
- PersonalizationDictionary.cs
- TiffBitmapDecoder.cs
- PenThread.cs
- MouseGesture.cs
- ListenerSessionConnectionReader.cs
- SoapTypeAttribute.cs
- Int64KeyFrameCollection.cs
- CompModSwitches.cs
- TextParagraphView.cs
- ActionItem.cs
- DataGridHeaderBorder.cs
- BaseDataListComponentEditor.cs
- __Error.cs
- UnsafeMethods.cs
- IncrementalHitTester.cs
- TextTreeUndoUnit.cs
- VersionedStream.cs
- IdentityReference.cs
- EncoderParameter.cs
- Helper.cs
- Helpers.cs
- AsyncResult.cs
- RoleManagerSection.cs
- XmlAttributeAttribute.cs
- ConsoleCancelEventArgs.cs
- TabItem.cs
- ColorIndependentAnimationStorage.cs
- mediaeventargs.cs
- basemetadatamappingvisitor.cs
- GC.cs
- PrimitiveSchema.cs
- MonikerUtility.cs
- TcpSocketManager.cs